Method of forming pin-eyes in metal bars.



I F. SCHAEFER. I METHOD OFFOBMING PIN'EYES IN M ETAh-BARS. {\PPLICATION FILED JUNE 2.19m.

1,270,059. Patented June 18, 1918.

FIGJ.

:WITNESSES FREDERIC SCH AEFER, 0F PITTSBURGH, PENNSYLVANIA;

METHOD OF FORMING PIN-EYES IN METAL BARS.

Specification of Letters Patent.

Patented June 18, 1918.

Original application med December 18, 1916, Serial No. 137,618. Divided and this application filed June 2,

' 1917. Serial No. 172,519.

forming pin eyes in metal bars.

The method is particularly useful for forming pin eyes in connecting bars for the brake levers of railway trucks or for push rods for brake cylinders and for other similar purposes where the bearing surface of the pin eyes cannot be below a certain minimum width.

.Bars of this character must be exceedingly strong, but it is also desirable to have them light, and at the same time it is requisite that the bearin surfaces of the pin eyes in the bars be 0 a certain width. In order to get the bearing surfaces around the pin eyes of required width, the metal of the bar is sometimes made thicker than necessary. If the thickness of the metal is increased, such material must be carried through the body of the bar and consequently the weight of the bar as well as its cost is increased. It has been proposed to draw the holes in the bar and thereby extrude the metal in one direction, but this process leaves the edges of the opening on the side opposite where the metal is extruded rounded in shape so that the actual bearing surface will not meet the requirements of practice without using metal of greater thickness than necessary 1 for other parts of the bar.

The present invention, relates to a method of forming the pin eyes in the bars such that a Wide bearing surface is provided without requiring that the metal ofthe bar be of a thickness greater than that required for the strains to which the bar is subjected.

It also relates to a method of forming a connecting bar that possesses a maximum strength for its weight and is reinforced at all the usual Weak points against bending or compression strains. A bar of this chan acter is described in my copending application-Serial No. 137,618, filed December 18,

I 1916, The present application is a division of the aforesaid case.

One of the objects of the present invention is to provide an improved method for forming pin eyes in metal bars so that extity tended bearing surfaces for the pivot pins are provided.

Another object is to provide an improved method of forming a connecting bar such that extended bearing surfaces are provided forpivot pins and, a maximum strength secured with a minimum amount of material.

Other objects and advantages of the invention will appear from the following specification The accompanying drawings illustrate an embodiment of the invention, the views of which are as follows Figure 1 is a plan view and a side elevation of the end of a metal blank in which pin eyes are formed, such blank being also of proper width for forming a connecting bar.

Figs. 2, 3, 4, and 5 are respectively a plan,

a longitudinal cross section, a bottom view and a lateral cross section at 5-5 of the bar, shown in Fig. 1 after it has been subjected to a die pressing or forging operation; Fig.6 is a plan and longitudinal cross sec- 1 tion on the line 6-6 of the end of the bar after it has been trimmed for forming a connecting bar;

Fig. 7 is a plan of a completed connecting bar after it is bent to shape;

Fig.8 is a side elevation of the bar shown in Fig. 7; 1

-Fig. 9 isa cross section on the line 9-9 of Fig. 8; i

Fig. 10 is a cross section on the line 10-10 of Fig. 8;

Fig. 11 is a cross section on the line 11-1l of Fig. 8; I y I F ig. 12 is a side elevation of a brake rod jaw in which the pin eyes are formed according to the improved method herein disclosed; and

Fig. 13 is a longitudinal cross section of the brake rod jaw shown in Fig. 12.

In the practice of the method, a metal blank is subjected to a die pressing or forging operation to form the pin eyes and extrude the metal in both directions from the body of the bar, the latter being made possible by reducing the thickness of the metal at other points to secure the necessary quanof metal to form the protuberanccs. The method is preferably carried out in substantially a single pressing operation but it may be carried out in two or more operations.

. around the openings.

-A metal blank 1, such as shown in Fig. l, is first subjected to a forging or a die pressingoperation to shape-it to the form illus trated in Fig. 2. Recesses or holes 2 are formed in the end of the bar by tapered punches 'or plungers which do not go quite tuberances 3 and 6 around the openings on the opposite side of the bar and with recesses or portions of reduced thickness 5 In the die pressing or forging operation, rough fins 7 are generally forced out which are subsequently sheared off in completing the bar. The above operation may be carried out for forming pin eyes in a bar without reference to the particular shape to which other portions of the bar are forged... One or more holes 2 may be provided and located in any suitable relation. In the particular bar illustrated the holes are spaced and located so that they are in proper position for a connecting bar.

vThe next operation which is a finishing operation consists in cutting out the bottoms 4 of the recesses to form holes entirely through the bar, and in shearing off the I rough portions of the bar and cutting it to t e desired'shape. At the same time the ho es through the bar may be straightened to' relieve them of the taper that is present as a result of the first operation, or this may be done by reaming after the bar is c'ompleged. The-completed bar is thus provided ithpin eyes or holes having extended bearing surfaces whlch have sharp 11111161 edges, thus reducing the stresses in pins which are subjected to load while inthe holes. The metal for such surfaces is taken from portions of the bar where it is not needed for strength, and consequently this metal may be used for the bar and. wide bearing surfaces provided without decreasing the strength of the bar.

If desired, the 'metal at the end of the bar where the pin eyes are formed may be further strengthened by reducing the thickness near the center and crowding toward the edges, giving the bar a cross section such as illustrated 'in Fig. 10. This thickening of the metal at the edges places the metal Where it adds to the strength of the bar by .reason of the I-b'eam or channel effect, as

will be readily understood. If the added strength is not needed in the bar, this thickening of the edges may be omitted. W'hcn the edges are thickened, however, such pro-- surfaces are formed.

In forming a connecting bar for railway trucks, the holes 2 are preferably formed in pairs in spaced relation, as shown, and the metal of the bar in line with the pair of holes is forced outwardly to form the portions 10 which are'for the'purpose of laterally strengthening the bar. tween the pairs of holes is also thinned at the point 11 and this portion, as well asthe rough flanges 7, is sheared out to leave two ears 12 which, when the bar is subsequently bent to shape, are directly opposite and parallel to each other. The shape of the finished bar is illustrated in Fig. 3, where the portion 11 and flanges 7 have been cut away and the'bottoms 4 of the openings 2 have been cutout and the surfaces of these openings straightened to relieve them of the taper shown in Fig. 2.

After the ends of the bar have been shaped, as shown in .Fig. 6, the bar is subjected to a further pressin or shaping operation which bends it to t e form shown in The metal be- Figs. 7 and 8. The body is given the shape illustrated in Fig. 11, and. the cars 12 at the ends of the bar are bent/ arallel to each other so that the'pin eyes are alined. This gi'ves a light bar of unusual strength.

The process herein disclosed for forming pin' eyes in the ends ofibars may be utilized.

for forming such pin eyes in bars for any suitable purpose, though it is particularly useful for forming s'ucheyes in devices used in connection with railways where the requirements are'veryv rigid for the bearing surfaces of openings in the bars. The pro- ,cess may beu'se'd, for example, in forming pin eyes in brake rod jaws, such as illustrated in Figs. 12 and 13, where the metal is extruded in both directions about the holes 15 and the metal thinned in the vicinity of the holes, as at 16.

It is, to be understood that the structures shown are for purposes of illustration only and that yariations may. be made therein and in the exact manner of carrying out the process, provided the same come within the spirit and scope of the appended claims.

What I claim is p 1. The method of forming pin eyes in metal bars, which comprises subjecting bar to a die pressing orforging operation to form holes therein and reduce the thickness of the metal in the vicinity of said holes and extrude the metal inv both directions from the body of the bar adjacent the hol s to provide extended bearing surfaces.

2. The method of formingpin eyesgirisk metal bars, which comprises "subjectin bar to a die pressing or forging operatiorr 130 to form holes therein and reduce the thick ness of the metal in the vicinity of the holes and away from the edges of the bar, and extrading the metal in both directions from the body of the bar adjacent the holes to provide extended bearing surfaces.

3. The method of forming pin eyes in thin metal bars, which com 'irises s'l'ibjecting a bar to a die pressing or forging operation to form a recess or recesses in said bar and reduce the thickness of the metal in the vicinity of said recesses and extrude it in both directions from the body of the bar immediately adjacent said recesses, and then subjecting said bar to a second operation for cutting out the bottom of said recess to form a hole through the bar and shaping the extruded portions to form extended bearing surfaces.

l. The method of forming pin' eycs in thin metal bars, which comprises subjecting a bar to a die pressing 0r forging operation to form a recess or recesses in said bar and reduce the thickness of the metal in the vicinity of said recesses and at a point removed from the edges of the bar and extrut ling it in both directitins from the body of the bar immediately. adjacent said recesses, and then subjecting said bar to a second operation to cut out the bottom of said recesses to form holes through the bar and shaping the extruded portions to form extended bearing surfaces.

5. The method of forming pin eyes in thin metal bars and strengthening said bars, which comprises subjecting a bar to a die pressing or forgii'ig operation to form holes therein, reduce the thickness of the metal in the vicinity of the holes and at points removed from the edges of the bars and extruding the metal in both directions at the body of the bar adjacent the holes to provide extended bearing surfaces. and also reducing the thickness of the metal near the center of the bar and increasing i is thickness near its edges to increase the strength of the bar.

(3. The method. of making a connecting bar having pin eyes With extended bearing surfaces, which comprises subjecting a single sheet of metal to a die pressing or forg- .ing operation to form spaced holes therein and reduce the thickness of the metal in the vicinity of said holes and extrude it in both directions from the body of the metal sheet adjacent the holes to provide extended bearing surfaces, slitting the ends of the bar to form ears with one or more of the holes on each ear, and bending the bar to form a body portion having oppositely disposed ears on its ends with the holes therein in alinement.

7. The method of making a connecting bar, which comprises subjecting a single sheet of metal to a (lie pressing or forging operation to form ears on the ends of the sheet with pin eyes in the ears. reducing the thickness of the metal on the line of the pin eyes and increasing the thickness adjacent the edges of the ears, and bending the metal sheet to form a tubular body with oppositely disposed cars at its ends with pin eyes in the adjacent ears in alinement.

8. The method of i'naking a connecting bar which comprises subjecting a single sheet. of metal to a die pressing or forging operation to form ears on the ends of the sheet and to form holes in the ears and reduce the thickness ol' the metal in the vicinity of said holes and at points removed from the edges of the cars and extruding the metal in both directions from the body of the ears adjacent the holes to provide extended hearing surfaces, and then bending said plate to form a tubular body with oppositely disposed cars at its ends with pin eyes in adja cent ears in alinemenl'.

5). The method of making a connecting bar, which comprises sulijccting a single sheet of metal to a die pressing or forging operation to form cars at the ends of the metal sheet to form recesses in said ears and reduce the thickness of the metal in the vicinity of said recesses and extruding the metal in both directions from the body of the ears adjacent the recesses and to reduce the thickness of the metal u anthe center ol the ears and increase its thickness at the edges, subjecting the ends of the bar to a second operation to cut out the metal in the bottom of the recesses and between the ears, and then bending the plate to form a tubular body with oppositely disposed cars at its ends having pin eyes in alinement.

in testimony whereof, I have hereunto set my hand.

FREDERIC SCHAE FER.

Witness:

GLENN ll. LERESCHE. 

